Like all dairy products, yogurt will turn bad really fast once you open it. One way to deal with this is to eat it as quickly as possible. Another one is to use a simple trick that will keep it fresh for longer.
We all know that it is important to keep both your opened and unopened dairy products in the fridge. But there is one extra step you can take to ensure yogurt lasts longer: store it upside down.
As it turns out, when you store your yogurt container upside down, you essentially create a vacuum. The lack of air will stop the bacteria that cause spoilage to grow. Of course, you just need to make sure that your yogurt container is sealed tightly to avoid it from spilling all over your fridge.
Another benefit of this storage technique is that the crystals that tend to form on the top of the yogurt are likely to form.
This trick should be used for unopened containers of yogurt as it will make them taste fresher even when sitting in the fridge for a longer period.
Keep in mind that spoilage can take place despite all the precautionary measures you take. If you notice that the yogurt has mold, a strange color, or tastes off, get rid of it.